Question

p0031 location oxigen sensor

Answer 1

bank 1 sensor 1 is located near the firewall on the exhaust manifold.

I would do an ECU reset (Clear Mixture Ratio Self-Learning) before replacing it. 

see step below, an easier way to do it is disconnect the battery for an hour or so.

1998-2014 Nissan Quest Clear Mixture Ratio Self-Learning Control Data